ASP.NET Tutorial/ASP.net Controls/Image
Содержание
Image alignment
<source lang="csharp">
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="Default_aspx" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server">
<title>Image Control</title>
</head> <body>
<form id="form1" runat="server">
Image Control
<asp:Image ID="img1" runat="server" AlternateText="Dan" ImageUrl="http://www.nfex.ru/style/logo.png" />
<asp:Button runat="server" Text="Sample Button" /> <asp:Image ID="img2" runat="server" AlternateText="Dan" ImageUrl="http://www.nfex.ru/style/logo.png" />
<asp:DropDownList ID="ddl" runat="server" AutoPostBack="True"> <asp:ListItem text="NotSet" /> <asp:ListItem text="AbsBottom" /> <asp:ListItem text="AbsMiddle" /> <asp:ListItem text="Top" /> <asp:ListItem text="Bottom" /> <asp:ListItem text="BaseLine" /> <asp:ListItem text="TextTop" /> <asp:ListItem text="Left" /> <asp:ListItem text="Right" /> </asp:DropDownList>
</form>
</body> </html> File: Default.aspx.cs using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class Default_aspx : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e) { switch (ddl.SelectedIndex) { case 0: img1.ImageAlign = ImageAlign.NotSet; img2.ImageAlign = ImageAlign.NotSet; break; case 1: img1.ImageAlign = ImageAlign.AbsBottom; img2.ImageAlign = ImageAlign.AbsBottom; break; case 2: img1.ImageAlign = ImageAlign.AbsMiddle; img2.ImageAlign = ImageAlign.AbsMiddle; break; case 3: img1.ImageAlign = ImageAlign.Top; img2.ImageAlign = ImageAlign.Top; break; case 4: img1.ImageAlign = ImageAlign.Bottom; img2.ImageAlign = ImageAlign.Bottom; break; case 5: img1.ImageAlign = ImageAlign.Baseline; img2.ImageAlign = ImageAlign.Baseline; break; case 6: img1.ImageAlign = ImageAlign.Middle; img2.ImageAlign = ImageAlign.Middle; break; case 7: img1.ImageAlign = ImageAlign.TextTop; img2.ImageAlign = ImageAlign.TextTop; break; case 8: img1.ImageAlign = ImageAlign.Left; img2.ImageAlign = ImageAlign.Left; break; case 9: img1.ImageAlign = ImageAlign.Right; img2.ImageAlign = ImageAlign.Right; break; default: img1.ImageAlign = ImageAlign.NotSet; img2.ImageAlign = ImageAlign.NotSet; break; } }
}</source>
Important properties of Image control
<source lang="csharp">
AlternateText: alternate text for the image required for accessibility. DescriptionUrl: a link to a page that contains a detailed description of the image (required to make a complex image accessible). GenerateEmptyAlternateText: set the AlternateText property to an empty string. ImageAlign: align the image relative to other HTML elements in the page. Possible values are AbsBottom, AbsMiddle, Baseline, Bottom, Left, Middle, NotSet, Right, TextTop, and Top. ImageUrl: specify the URL to the image.
<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server">
void Page_Load() { Random rnd = new Random(); switch (rnd.Next(3)) { case 0: imgRandom.ImageUrl = "Picture1.gif"; imgRandom.AlternateText = "Picture 1"; break; case 1: imgRandom.ImageUrl = "Picture2.gif"; imgRandom.AlternateText = "Picture 2"; break; case 2: imgRandom.ImageUrl = "Picture3.gif"; imgRandom.AlternateText = "Picture 3"; break; } }
</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server">
<title>Show Image</title>
</head> <body>
<form id="form1" runat="server">
<asp:Image id="imgRandom" Runat="server" />
</form>
</body> </html></source>
Load Image to asp:Image
<source lang="csharp">
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server">
<title>Untitled Page</title>
</head> <body>
<form id="form1" runat="server">
<asp:Label ID="Label1" runat="server" Height="32px" Text="Image to display" Width="176px"></asp:Label> <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" Width="112px"> <asp:ListItem>A</asp:ListItem> <asp:ListItem>B</asp:ListItem> </asp:DropDownList>
<asp:Image ID="Image1" runat="server" AlternateText="Image" Height="128px" ToolTip="Image"Width="208px" />
</form>
</body> </html>
File: Default.aspx.vb
Partial Class _Default
Inherits System.Web.UI.Page Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click Select Case DropDownList1.SelectedIndex Case 0 Image1.ImageUrl = "http://www.nfex.ru/style/logo.png" Case 1 Image1.ImageUrl = "http://www.nfex.ru/style/logo.png" End Select End Sub
End Class</source>
Set ImageUrl and AlternateText for asp:Image (VB.net)
<source lang="csharp">
<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server">
Sub Page_Load() Dim rnd As New Random() Select Case rnd.Next(3) Case 0 imgRandom.ImageUrl = "Picture1.gif" imgRandom.AlternateText = "Picture 1" Case 1 imgRandom.ImageUrl = "Picture2.gif" imgRandom.AlternateText = "Picture 2" Case 2 imgRandom.ImageUrl = "Picture3.gif" imgRandom.AlternateText = "Picture 3" End Select End Sub
</script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server">
<title>Show Image</title>
</head> <body>
<form id="form1" runat="server">
<asp:Image id="imgRandom" Runat="server" />
</form>
</body> </html></source>